Up to now, in order to improve the feeling when using cosmetics, compositions for skin, and the like, especially feeling of cosmetic film, gloss, and moisture feeling, highly viscous hydrocarbon liquid oils such as wax and polybutene have been used. Since polybutene is a raw material that is excellent in improving feeling of cosmetic film and gloss and has a long-lasting feeling of cosmetic film, it is widely used in cosmetic compositions for makeup (Patent Literatures 1, 2 and 3).
However, when increasing an amount of polybutene in the cosmetic compositions in order to further improve the long-lasting feeling of cosmetic film, sticky feeling becomes stronger and the results are not always satisfactory. In addition, the hydrate ability of polybutene is very low because it is a nonpolar liquid oil. As a result, it sometimes causes make-up deterioration caused by perspiration through the skin and the like in case of formulating polybutene in cosmetic compositions or compositions for skin. Thus, polybutene is not always satisfactory in respect of making make-up last longer.
As raw materials of the cosmetic compositions that are excellent in the sense of use such as feeling of cosmetic film and richness, a polyglyceryl isostearic acid using a 2-(1,3,3-trimethyl)butyl-5,7,7-trimethyl octanoic acid as a fatty acid has been developed and reported (Patent Literature 4). However, the viscosity of the polyglyceryl isostearic acid is 35,000 mPa·s at the maximum value, and it cannot be used in cases that use of the products having the high viscosity of 100,000 mPa·s or higher is required in order to further improve functions such as pigment dispersibility and lastingness of cosmetic film.
Besides, oil solvents containing esterified compounds that are composed of multiple branched fatty acids and alcohol have been developed (Patent Literature 5). However, this literature discloses that the viscosity of the obtained esterified compounds is 30,000 mPa·s at the maximum value, and the production methods described therein sometimes generate the products having a high cloud point. Therefore, the products thus produced are not always satisfactory in respect of quality.
Further, the Patent Literature 6 discloses that a 2-(1,3,3-trimethyl)butyl-5,7,7-trimethyl octanoic acid is used as one component of an external drug wherein a medicinal drug is effectively absorbed transdermally or absorbed in the stratum corneum, but any study therein on the ester compositions obtained by esterification with alcohols has not been made.
[Patent Literature 1] Japanese Patent Unexamined Publication No. Hei 9-151111
[Patent Literature 2] Japanese Patent Unexamined Publication No. 2002-3340
[Patent Literature 3] Japanese Patent Unexamined Publication No. 2002-316910
[Patent Literature 4] Japanese Patent Unexamined Publication No. 2003-113025
[Patent Literature 5] WO03/055451 A1
[Patent Literature 6] Japanese Patent Publication No. 2-207018